Process of making battery-depolarizers.



HARRY FBENGHAND EAYMONQDC. BENNER, or FREMONT, OHIO, ASSIGNORS, BY M snAssIGNMENTs, T0 NATIONAL cARBoNcoMPANY, INC., A oonrona'rron or NEWYORK.

PROCESS OF MAKING BATTERY-DEPOLABIZERS.

1,269,173. .No'Drawing.

vented a certaln-new and useful Improvement in Processes of MakingBattery-Depolarizers, (Docket No. 268,) of which the following isa-full, clear, and exact description.. I

This'invention relates to electric batteries of the Lalande type. Inthis kind of battery copper oxid used as the negative element and isopposed to av zinc electrode in an alkaline electrolyte,.such as sodiumor potassium hydroxid. In the application of Raymond \V. Erwin, filedNov.' 30, 1915, Serial Number 04,342, means is disclosed for raising thevoltage of this type of batter consisting in the addition of sulfur tothe copper oxid mass. e have found a new process for making adepolarizer for producing such an increase in voltage, as will now beset forth in detail.

V0 mix copper oxid or partially oxidized copper scale with sulfur andheat to such a temperature as will cause a reduction of the copper oxideither wholly or in part. There are a number of reactions that can takeplace, depending upon various conditions, such as temperature, time ofheating, etc, and several of such reactions are given below:

It is. desirable to maintain conditions to produce the reducing reactionfor the greater part in accordance with the first mentioned equation, asa large amount of cuprous'sulfid (C153) is harmful to the should also ofthis material is harmful to the cell. The process. however, can he socontrolled that. but small amounts are formed; and in case of largerquantities one or two leaching operations are included in the laterinoisteuing process.

Our mixtures are made in the proportion of about 20 parts of sulfur to Wparts (by copies or this patent may'be obtained for Specification ofLetters Patent.

the starting material.

Weight) of copper oxid. It is permissible to reduce this sulfulproportion according to the amount of metallic copper present in We findthat the proportion given is the optimum, although a high voltagedepolarizer is obtained with amounts of'sulfur as low as 3%.

The mixture. is heated for several hours between 300 and 800 C. Thereaction takes place very slowly, or not at all, below 300 and on theother hand there is danger of fusion if the material reaches too high atemperature. A very satisfactory point is about 600 C. The'heatingshould be conductedi'n a covered vessel nearly filled with material toavoid as far as possible the presence of air;

The roasted mass is then oxidized by moistening with water, orpreferably with sodium hydroxid solution, and allowing it to stand inthe air until oxidation is substantially complete.

It is not necessary to reduce the copper by sulfur alone. It ispermissible to add less sulfur than that required and then complete thereduction by passing over'the heated mixture some reducing agent, suchas hydrogen, or other gas which may have the power of reducing the oxidof copper..

Also the sulfids of copper (Cu S, CuS, etc.) either natural 'orartificial, maybe changed-over into'the high voltage depolarizer byroasting and then reoxidizing by means of air as previously described.This produces a depolarizer at low cost.

HtlYlllgtlGSCI'lbQd my invention, what I.

claim is:-

1. The process of making a battery de polarizcr which consists inreducing copper oxid with an excess of sulfur and then reoxidizing thereduced mass in'the presence of the excess sulfur.

2. The process of making a battery depolarizer which consists inreducing copper oxid with an excess of sulfur, moisteni'ng the reducedcopper and excess sulfur with sodium. hydroxid solution, and thenreoxidizing in the air.

In testimony whereof, we our signatures.

HARRY F. FRENCH. RAYMOND 0. Banana.

hereunto attix five cents each, by addressing the "Commissioner of.l'atenti,

Washington, D. G.

Patented June 11,1918.

Application filed-November 21, 1916. Serial in). 132,556.

